The standard technique for studying gastric emptying is the nuclear medicine gastric emptying study which involves the administration of a food that has been mixed with labeled Tecnetium-sulfur-colloid. Over the past 15 years, we have been involved in studying the kinetics of absoption utilizing a D-xylose model that requires the oral and intravenous administration of D-xylose, followed by frequent blood and urine determinations of D-xylose concentration. In addition to providing information about the absorption and disposition of D-xylose, these studies also give data on the lag phase, or the time preceding absorption, which relates to gastric emptying. Our kinetic model will be utilized for both liquid D-xylose and D-xylose administered with food. The results will be compared to the standard nuclear medicine test of gastric emptying. The data obtained will provide additional data on the D-xylose test, and it might provide a relatively simple test of gastric emptying that does not involve the use of radionuclide.